Minding your own business, at its heart, is focusing on what you can control and letting go of what you can’t. It is taking responsibility for your own thoughts and actions, and letting other people take responsibility for their own thoughts and actions.
So often we try to control other people, control the world around us, and basically control everything and everyone but ourselves.
Ironically, the only thing we CAN control is ourselves. And even then, it’s imperfect control.